I had over 10,000 pictures that I was loading onto my Ipad 1. Here are some notes for what it is worth, I am a die-hard PC user and got an Ipad after I was impressed with the Macbook Pro my I got my daughter held up so well and never got any frantic calls about viruses or other OS related issues.
1. The original Itunes and Ipad firmware was the best from the POV of synching pictures, it was a plug and forget affair and I had jpegs, tiffs, raw files, movies (MP4 format) all loaded in there, over 40 GB worth with no issues! However, Itunes in the earlier version (2009 December) would not synch applications properly (those downloaded on the Ipad directly) in case you had to restore the Ipad, please correct me if I am wrong, since the latest Itunes (september 2011) does this perfectly, including all updates to the downloaded applications and latest firmware, and I have had to restore at-least once.
2. In around June/July 2011 (I'm too lazy to remember Itunes version and Ipad firmware version) this all changed! I started having Itunes crashes, usually at the end of optimizing photos. I had huge folders, some as large as 5000 photos, and was having Itunes look through some 15,000 photos. Thats when I joined this forum and found a lot of helpful FAQs, i.e. how to re-boot the Ipad when Safari freezes (have done this only once in 3 years), putting applications into folders, etc.
3. I'm a real risk-averse person and avoid something if the downside is something I cannot accept, period. For example, I am never going to use my 64GB Ipad as a back-up storage for my Camera CF/SD cards if I have not a back-up on a PC (or Mac in the future), because Apple's manuals and help at the Apple store are kinda poor, when it comes to photos. Similarly, I know now that you can synch to only one computer, and not more. I didn't try it since there was no need to find out.
4. Here is what I found for Itunes crashes, the hard way, and there is some degree of uncertainty in my following statements. Since I have not found any Apple or authoritative statements otherwise, so take it for what it is worth as my experience. Itunes is a 32 bit software, as opposed to 64 bit, the reasons for this in today's market, is a mystery. My computer is an I7 with 12 MB ram, and over 1TB free on the HD. I have very rarely had a crash in software in my 64bit Vista, the only ones are IE based ones every other week or so, and are usually recovered automatically. Being 32 bit, it has problems with large data sets, it only uses 3.4 GB of memory (based on windows Task Manager) at any time, with the rest on the 12 MB sitting idle. This causes it to crash when I upload more than 2000 files or 2GB at a time. When it crashes, it probably corrupts the "Ipod photo cache" folder (under documents) where it stores synch information for future synchs.
5. My work around is as follows: First, no need to reboot the Ipad or PC before you start the synch process, but it does not hurt, just uses up 5 minutes. I did not do it the last few times when Itunes crashed, so I think it's not necessary. Second, break up your large folders so they stay under 2000 files or 2GB each. Remove any RAW, TIFF or MVI files, keep nothing but JPEGS and MP4 files for folders you will synch later. Third, delete the folder Ipod Photo cache so that Itunes can "rebuild it" from scratch. Fourth, when you get ready to synch, go to the Ipad tab on Itunes right away, hit only selected folders (unselect all folders and movies) to begin with. Note that when you start to synch, you may get a message asking to delete existing files on the Ipad (since you deleted the cache), go ahead and delete it so that the possibly corrupted cache (caused by the Itunes crashes) can be built from scratch again.
6. In your folder tree, where it shows folders with pictures and movies, remember where all your TIFF, RAW and MVI files are so you don't tick them for synch later!!
7. Now synch (upload) folders so that you don't exceed the limits of 1500~2000 files or 2GB (in my case, your mileage may vary!)
8. Synch videos from a separate folder after ticking (include videos) so that you limit this to about 20 files and 1 GB max (again, in my case this works, your mileage may vary)
9. I use a program called Aiseesoft to convert MVI videos from my camera(s) to MP4 format, others may be available, and Itunes probably does it too when you drag and drop into Itunes, but I don't do this, again, because documentation is poor or non-existent or buried somewhere.
Once you synch all your photos and videos, synch as soon as you get a few hundred new photos in any folder, or 5~10 videos.
Another note, Itunes crashes can be caused by photos and videos it "does not like" (with no messages as it used to in previous version), so if it crashes when a certain folder is being synched (mine did with a couple of videos that it had no issues with earlier, and play fine on my PC) then drag all the files out of that folder and feed them into that folder a few at a time until you encounter the crash, then label them so you know not to have them in the folder for synch in the future, or recreate them from the original MVI file (I haven't tried this since the videos weren't important enough).
I know all this is a pain, buts the only way I know to get over 10,000 photos/videos into the Ipad, which is great having them there for reviewing or watching with others on the fly. Future synch's go pretty fast, 2~3 minutes, considering I have so many files there.
I wonder why Apple (and for that matter MS) don't give you a list of what does NOT work, so we can all save time? Could be they may include those features in an update and save time by not having to send new documentation to users, or it could be just some overtime legal advice not to do so.
Hope this helps someone!